// video.js
// Copyright (C) 2024 DTP Technologies, LLC
// All Rights Reserved

'use strict';

import fs from 'node:fs';
import path from 'node:path';

import mongoose from 'mongoose';
const Video = mongoose.model('Video');

import mime from 'mime';
import numeral from 'numeral';

import { v4 as uuidv4 } from 'uuid';

import { SiteService, SiteError } from '../../lib/site-lib.js';
import user from '../models/user.js';

const ONE_MEGABYTE = 1024 * 1024;
const SIZE_100MB = ONE_MEGABYTE * 25;
const SIZE_25MB = ONE_MEGABYTE * 25;

const MAX_VIDEO_BITRATE = 4000;

export default class VideoService extends SiteService {

  static get name ( ) { return 'VideoService'; }
  static get slug ( ) { return 'video'; }

  constructor (dtp) {
    super(dtp, VideoService);
  }

  async start ( ) {
    const { user: userService } = this.dtp.services;
    await super.start();

    await fs.promises.mkdir(process.env.VIDEO_WORK_PATH, { recursive: true });

    this.populateVideo = [
      {
        path: 'owner',
        select: userService.USER_SELECT,
      },
      {
        path: 'thumbnail',
      },
    ];
  }

  async createVideo (owner, videoDefinition, file) {
    const NOW = new Date();
    const { media: mediaService, minio: minioService } = this.dtp.services;

    this.log.debug('video definition in createVideo', { videoDefinition });

    this.log.debug('running ffprobe on uploaded library media', { path: file.path });
    const metadata = await mediaService.ffprobe(file.path);
    this.log.debug('video file probed', { path: file.path, metadata });

    if (user.membership) {
      if (file.size > SIZE_100MB) {
        throw new SiteError(403, 'Video attachments are limited to 100MB file size.');
      }
    } else {
      if (file.size > SIZE_25MB) {
        throw new SiteError(403, 'Video attachments are limited to 25MB file size.');
      }
    }

    const video = new Video();
    video.created = NOW;
    video.owner = owner._id;
    video.duration = metadata.duration;
    video.status = 'new';

    if (!videoDefinition.fromGif) {
      videoDefinition.fromGif = false;
    }
    video.flags = {
      fromGif: videoDefinition.fromGif,
    };

    const ownerId = owner._id.toString();
    const videoId = video._id.toString();
    const fileBucket = process.env.MINIO_VIDEO_BUCKET || 'videos';
    const mediaExt = mime.getExtension(file.mimetype) || 'dat';
    const fileKey = `/video/${ownerId.slice(0, 3)}/${ownerId}/${videoId.slice(0, 3)}/${videoId}/media.${mediaExt}`;

    this.log.debug('uploading video to storage', {
      _id: video._id,
      bucket: fileBucket,
      key: fileKey,
      path: file.path,
    });

    await minioService.uploadFile({
      bucket: fileBucket,
      key: fileKey,
      filePath: file.path,
      metadata: {
        'Video-ID': videoId,
        'Content-Type': file.mimetype,
        'Content-Length': file.size,
      },
    });

    video.media = {
      bucket: fileBucket,
      key: fileKey,
      metadata: {
        type: file.mimetype,
        size: metadata.format.size,
        bitRate: metadata.format.bit_rate,
        duration: metadata.duration,
        video: {
          width: metadata.width,
          height: metadata.height,
          fps: metadata.fps,
        },
      },
    };

    await video.save();

    await this.extractVideoAttachmentThumbnail(video, file);

    return video.toObject();
  }

  async extractVideoAttachmentThumbnail (video, file) {
    const { media: mediaService } = this.dtp.services;
  
    const thumbnailFile = path.join(process.env.VIDEO_WORK_PATH, `${video._id}.png`);
    const ffmpegThumbnailArgs = [
      '-y', '-i', file.path,
      '-ss', numeral(video.media.metadata.duration * 0.05).format('hh:mm:ss'),
      '-frames:v', '1',
      thumbnailFile,
    ];
  
    this.log.debug('extracting video thumbnail', { ffmpegThumbnailArgs });
    await mediaService.ffmpeg(ffmpegThumbnailArgs);
  
    this.log.info('persisting thumbnail to video', { videoId: video._id });
    await this.setVideoThumbnailImage(video, thumbnailFile);
  }

  async setVideoThumbnailImage (video, thumbnailFile) {
    const { image: imageService } = this.dtp.services;

    await this.removeVideoThumbnailImage(video);

    const imageFileDesc = { path: thumbnailFile };
    const outputs = [
      {
        width: 960,
        height: 540,
        format: 'jpeg',
        formatParameters: { quality: 95 },
      }
    ];
    await imageService.processImageFile(
      video.owner._id,
      imageFileDesc,
      outputs
    );

    await Video.updateOne(
      { _id: video._id },
      { $set: { thumbnail: outputs[0].image._id } },
    );

    return outputs[0].image._id;
  }

  async removeVideoThumbnailImage (video) {
    const { image: imageService } = this.dtp.services;

    if (!video.thumbnail) {
      return;
    }

    this.log.info('removing current video thumbnail', { videoId: video._id });
    await imageService.deleteImage(video.thumbnail);
    await Video.updateOne({ _id: video._id }, { $unset: { thumbnail: 1 } });

    delete video.thumbnail;
  }

  async setVideoStatus (video, status) {
    await Video.updateOne({ _id: video._id }, { $set: { status } });
  }

  async getVideoById (videoId) {
    const video = await Video
      .findOne({ _id: videoId })
      .populate(this.populateVideo)
      .lean();
    return video;
  }

  async removeVideo (video) {
    const { minio: minioService } = this.dtp.services;

    if (video.thumbnail) {
      await this.removeVideoThumbnailImage(video);
    }

    if (!video.media || !video.media.bucket || !video.media.key) {
      return;
    }

    await minioService.removeObject(video.media.bucket, video.media.key);
    await Video.deleteOne({ _id: video._id });
  }

  async removeForUser (user) {
    this.log.info('removing all videos for user', {
      user: {
        _id: user._id,
        username: user.username,
      },
    });
    await Video
      .find({ owner: user._id })
      .populate(this.populateVideo)
      .cursor()
      .eachAsync(async (video) => {
        await this.removeVideo(video);
      });
  }

  async transcodeMov (file) {
    const { media: mediaService } = this.dtp.services;

    const probe = await mediaService.ffprobe(file.path);
    const videoStream = probe.streams.find((stream) => stream.codec_type === 'video');
    const audioStream = probe.streams.find((stream) => stream.codec_type === 'audio');
    this.log.info('Quicktime MOV probe result', { probe });

    const transcodeArgs = ['-y', '-i', file.path];

    if (videoStream && (videoStream.codec_name === 'h264')) {
      transcodeArgs.push('-c:v', 'copy');
    } else {
      let needScale = false;

      /*
       * If the width isn't divisible by 2, adapt.
       */
      if (probe.width && ((probe.width % 2) !== 0)) {
        probe.width = Math.floor(probe.width / 2) * 2;
        needScale = true;
      }

      /*
       * If the height isn't divisible by 2, that needs to be fixed.
       */
      if ((probe.height % 2) !== 0) {
        probe.height = Math.floor(probe.height / 2) * 2;
        needScale = true;
      } else if (probe.height && (probe.height > 540)) {
        probe.height = 540;
        needScale = true;
      }

      if (needScale) {
        transcodeArgs.push('-vf', `scale=${probe.width}:${probe.height}`);
      }

      /*
       * Software: libx264
       * GPU: h264_nvenc
       */
      transcodeArgs.push('-pix_fmt', 'yuv420p');
      transcodeArgs.push('-c:v', 'libx264');

      /*
       * If bit rate is too high, correct it.
       */
      probe.format.bit_rate = parseInt(probe.format.bit_rate, 10);
      probe.format.bit_rate = Math.round(probe.format.bit_rate / 1024);
      this.log.info('detected bit rate', { bitrate: probe.format.bit_rate });
      if (probe.format.bit_rate > MAX_VIDEO_BITRATE) {
        transcodeArgs.push('-b:v', `${MAX_VIDEO_BITRATE}k`);
      } else {
        transcodeArgs.push('-b:v', `${probe.format.bit_rate}k`);
      }

      transcodeArgs.push('-profile:v', 'high');
    }

    if (audioStream && (audioStream.codec_name === 'aac')) {
      transcodeArgs.push('-c:a', 'copy');
    } else {
      transcodeArgs.push(
        '-c:a', 'aac',
        '-b:a', '160k',
      );
    }

    file.uuid = uuidv4();
    const outFile = path.join(process.env.VIDEO_WORK_PATH, `${file.uuid}.mp4`);
    transcodeArgs.push(
      '-movflags', '+faststart',
      outFile,
    );

    this.log.info('transcoding Quicktime MOV video to MP4');
    await mediaService.ffmpeg(transcodeArgs);

    await fs.promises.rm(file.path, { force: true });
    file.path = outFile;
  }

  async transcodeGif (file) {
    const { media: mediaService } = this.dtp.services;

    const probe = await mediaService.ffprobe(file.path);
    this.log.info('GIF probe result', { probe });

    const transcodeArgs = ['-y', '-i', file.path];

    let needScale = false;

    /*
     * If the width isn't divisible by 2, adapt.
     */
    if (probe.width && ((probe.width % 2) !== 0)) {
      probe.width = Math.floor(probe.width / 2) * 2;
      needScale = true;
    }

    /*
     * If the height isn't divisible by 2, adapt.
     */
    if (probe.height && ((probe.height % 2) !== 0)) {
      probe.height = Math.floor(probe.height / 2) * 2;
      if (probe.height > 540) {
        probe.height = 540;
      }
      needScale = true;
    } else if (probe.height && (probe.height > 540)) {
      probe.height = 540;
      needScale = true;
    }

    if (needScale) {
      transcodeArgs.push('-vf', `scale=${probe.width}:${probe.height}`);
    }

    transcodeArgs.push('-pix_fmt', 'yuv420p');
    transcodeArgs.push('-c:v', 'libx264');

    /*
     * If bit rate is too high, correct it.
     */
    probe.format.bit_rate = Math.round(parseInt(probe.format.bit_rate, 10) / 1024);
    this.log.info('detected bit rate', { bitrate: probe.format.bit_rate });
    if (probe.format.bit_rate > MAX_VIDEO_BITRATE) {
      transcodeArgs.push('-b:v', `${MAX_VIDEO_BITRATE}k`);
    } else {
      transcodeArgs.push('-b:v', `${probe.format.bit_rate}k`);
    }

    transcodeArgs.push('-profile:v', 'high');
    transcodeArgs.push('-an');

    file.uuid = uuidv4();
    const outFile = path.join(process.env.VIDEO_WORK_PATH, `${file.uuid}.mp4`);
    transcodeArgs.push('-movflags', '+faststart', outFile);

    this.log.info('transcoding GIF video to MP4');
    await mediaService.ffmpeg(transcodeArgs);

    await fs.promises.rm(file.path, { force: true });
    file.path = outFile;
  }
}